Field of the Invention
The present invention relates to a microphone device in which a microphone unit is attached inside microphone case with a cushioning member, and especially relates to a microphone device in which an arrangement of a microphone cable that leads out an electrical signal from the microphone unit is improved.
Description of the Related Art
In a case of a handheld microphone, a user directly holds the body of a microphone case. Therefore, applied vibration and acceleration are easily transmitted to the microphone unit in the microphone case. This generates a vibration noise called touch noise or handling noise.
Therefore, in this sort of microphone device, to prevent generation of the vibration noise, a configuration is employed in which the microphone unit is attached inside the microphone case with a cushioning member formed with a rubber material, and this microphone device is disclosed in patent publications, such as JP 2015-5942 A and JP 2008-177633 A.
The cushioning member that supports the microphone unit functions as a vibration isolator of the microphone unit and has a natural frequency of vibration, i.e. a resonant frequency. Therefore, when the cushioning member holding the microphone unit receives external vibration resonates, this causes to generate and output a large vibration noise output. Therefore, the resonant frequency needs to be set to a lower frequency band outside a sound collecting band of the microphone unit, or to a lower frequency band the noise at which seems to be inconspicuous even within the sound collecting band.
To achieve this, a high compliant material needs to be selected as the material of the cushioning member that functions as a vibration isolator, and accordingly the microphone unit can move in a large movable range in the microphone case.
Meanwhile, a microphone cable that leads an electrical signal from a microphone unit is connected between the microphone unit supported by the cushioning member and the microphone case that accommodates the microphone unit.
FIGS. 7 to 10 exemplarily illustrate the above-described arrangement of the microphone cable in the conventional microphone device including a cushioning member.
Note that the conventional microphone device illustrated in FIGS. 7 to 10 includes members that serve the same functions as an embodiment according to the present invention illustrated in FIGS. 1 to 6, described below, and the members are illustrated with the same reference signs. Therefore, detailed configurations of respective portions will be described below based on FIGS. 1 to 6.
A microphone cable 45 in the conventional microphone device is arranged in a space along a nearly central portion of a microphone case 30, without forming slack as possible in a substantially linear manner, and connects between a microphone unit 10 and a connector 47, as exemplarily illustrated in FIG. 7.
According to the configuration illustrated in FIG. 7, the microphone cable 45 is arranged in a state of floating in the air in a space portion between a microphone unit 10 and a connector 47. Therefore, vibration received by a microphone case 30 is transmitted to the microphone unit 10 from the connector 47 through the microphone cable 45, as schematically illustrated by the broken line. Accordingly, the vibration noise is generated.
To prevent the generation of the vibration noise through the microphone cable 45, use of a thinner wire can be suggested as the microphone cable 45.
However, when the microphone device is dropped and a large shock is applied to the microphone device, the microphone unit 10 instantly swings largely with being held by cushioning members 41 and 42. Accordingly, a problem occurs that an unreasonable tension is applied to the microphone cable 45 and the microphone cable 45 may be disconnected, as illustrated in FIG. 8.
Therefore, when sufficient looseness is provided to the microphone cable 45 connected to between the microphone unit 10 and the connector 47, as illustrated in FIG. 10, disconnection of the microphone cable 45 can be prevented if a large shock is applied to the microphone device, as described above. In this case, however, the microphone cable 45 freely vibrates, and the free vibration of the microphone cable 45 is transmitted to the microphone unit 10, as illustrated in FIG. 9, and this may cause to generate the vibration noise.
That is, the bi-directional arrow illustrated in FIG. 9 illustrates a state that the microphone cable 45 freely vibrates, and the broken line schematically illustrates a situation where the vibration of the microphone cable 45 is transmitted to the microphone unit 10.